Fortinet FortiOS < 5.2 / 5.4.x < 5.4.6 / 5.6.x < 5.6.1 SSL / TLS Renegotiation Handshakes MitM Plaintext Data Injection (FG-IR-17-137)

high Nessus Plugin ID 104656


The remote host is affected by a MITM vulnerability.


The version of Fortinet FortiOS running on the remote device is 5.2.x or prior, 5.4.x prior to 5.4.6, or 5.6.x prior to 5.6.1. It is, therefore, affected by a MITM vulnerability in SSL Deep-Inspection due to insecure TLS renegotiation.


Upgrade to Fortinet FortiOS version 5.4.6 / 5.6.1 or later.

See Also

Plugin Details

Severity: High

ID: 104656

File Name: fortios_FG-IR-17-137.nasl

Version: 1.7

Type: local

Family: Firewalls

Published: 11/17/2017

Updated: 4/29/2021

Risk Information

CVSS Score Source: CVE-2009-3555


Risk Factor: Low

Score: 3.3


Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.5

Vector: AV:N/AC:M/Au:N/C:N/I:P/A:P

Temporal Vector: E:POC/RL:OF/RC:C


Risk Factor: High

Base Score: 7.4

Temporal Score: 6.7

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Temporal Vector: E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:fortinet:fortios

Required KB Items: Host/Fortigate/model, Host/Fortigate/version

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 11/3/2017

Vulnerability Publication Date: 11/3/2017

Reference Information

CVE: CVE-2009-3555

BID: 36935

CWE: 310